During the period spanning 1964 to 1990, mathematics and theoretical computer science advanced through a consolidation of rigorous formalism in probability, computation, and logic. Researchers emphasized axiomatic rigor, computability, and constructive reasoning, bridging mathematics with algorithmic thinking. The era saw the emergence of formal treatments of probability, theory-change and belief revision, and the integration of constructive methods into analysis, fueling methodological shifts toward explicit constructions and verifiable proofs. This synthesis fostered cross-disciplinary collaboration, setting the stage for later developments in cryptography, logic in computing, and formal verification.